Vehicle-brake mechanism



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Filed June 12, 1926 aging man? N. A. CHRISTENSEN vsHIcLE BRAKE nacmmrsl .June 25, 1929.

Filed June 12, 1926 2 Sheets-Sheet Patented June 25, 1929.

UNITED STATES NIELS A. CHRISTENSEN, F CLEVELAND, OHIO.

VEHICLE-BRAKE MECHANISM.

Bussum Application filed June 12, 1926, Serial No. 115,604. Renewed May '12 1928.

The invention relates to brakes for automotive vehicles and trailers for such vehicles. t

The object of the invention is to provlde a. wheel brake mechanism wherein-the brake member is a shoe which is pivotally mounted and supported adjacentone end upon a link pivotally connected to a brake support and is moved into braking engagement with its drum by pressure applied to the other end of the shoe, and more particularly by a fiuidpressure-operated motor mounted with the brake drum, the construction and arrangement being such as to distribute the braking pressure substantially uniformly along the surface of the shoe, thereby preventing unequal wear ofthe braking surfaces and providing for eiiicient braking contact and hence eiiicient braking action.

The invention further consists in the several features hereinafter set forth and more particularly defined byclaims at the conclusion hereof.

In the drawings Fig. 1 is a sectional view ofbrake mechanism embodying the invention viewed along the section line 1-1 of Fig. 2 where said mechanism is shown associated with the front wheel;

Fig. 2 is .i section taken on the line 2-2 of 1;

Fig. 3 is a detail sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a view similar to Fig. 1, showing a modification;

Fig. 5 is a detail sectional view taken on the line 55 of Fig. 4;

Fig. 6 is a detail sectional view taken on the line 6 6 of Fig. 4;

Fig. 7 is a detail sectional view taken on the line 7-7 ofy Fig. 4.

In Figs. 1 to 3 of the drawings the numeral 10 designates the brake drum for the front wheel, suitably bolted to the hub 11 and spokes 11 of said wheel, the hub being journalled on the stub axle formed integral with the steering knuckle 12 mounted to swing about the pivot pin 13 carriedby the front axle 14, and a brake support 15 in the form of a dished plate is secured to a flat surface 16 of the knuckle by bolts 17.

A pair of brake shoes 18 work within the drum 10. Each brake shoe is connected toy an anchor pin 19 adjacent one end and one end 20 of an anchor pin link 21 is pivotally mounted on a pin 24 fixed to the brake support 15, the bifurcations of one link straddling those of the other link and held against longitudinal movement on the pin by a washer 23 and bolt 24. Thus both links 21 are mounted on the same supplorting pin 24 60 and each link carries a brake s oe.' To limit the swinging movement of the shoe, in its release position, relative to the link, each link has a lug 25 in which a set or stop-screw 26 is mounted which is adapted to engage 65 with a stop lug 27 on the brake support 15 when the shoe is in its release position, said screw 26 being locked in adjusted position b a nut 28. To move the lower ends of the s oes to release position a spring 29 is con- 70 nected at one end to a lug 30 on each link and to an anchor pin 31 on the brake support at its other end. Theupper ends'of the shoes are moved to release position by a spring 32 connected at its ends to said shoes. 75

With this construction when the free ends of the shoes are thrust outwardly the shoes will be moved into braking engagement Awith the drum 10 and owing to the link connection above described, each shoe moves relative to and with the link so as to bring substantially its entire braking surface into contact with `the drum, and the links are made very short so as to obtain an eflicient braking effect. The shoes may be provided with -85 Figs. 1 and 2, a luid-pressur'e-operated mo- 90 tor including a brake cylinder 3,4 having a pair of suitably packed pistons 35 worklng in its bore in opposite directions, with their piston-rods extending beyond the heads of the cylinder and having polygonal heads 36 g5 4with a vertically-disposed slot 37 therein. AJ

jack-screw 38 has its threaded shank adjustably mounted in the free end of each brake shoe and secured by a nut 39 in adjusted position so as to determine the release I position of this end of the shoe, and has a flattened head 40 engaging in the slot 37 of the head-36 whereby a thrust connection between a moving part ofthe motor is provided and whereby the shoe is held against lateral movement relative to the drum. The brake cylinder 34 is secured by bolts 41 to the support l5 and when a fluid-pressure medium, such as compressed air,l is introduced into said cylinder between the pistons 11o is pivotally mounted above described,

said pistons will move outwardly and thus move said shoes into braking engagement with said drumin the manner previously described.

l Where an increase of braking pressure over that provided by a direct connection between the motor and the shoes is desired, the construction shown in Figs. 4 to 7 inclusive, is' used. In this construction the brake shoes 18 being similarly anchored and supported as in the first-described construction like reference numerals refer to these parts and the fluid-pressure-operated motor is also the same. The differences reside principally in the interposition of a multiplying lever 42 between the head 36 of each piston and an adjustable jack-screw 43 associated with the free end of each brake shoe. Each lever 42 at one end upon a .pin formed integral with ofthe motor and its free end is flattened to fit into the slot 37 of the head 36 of the piston rod while it has a flat-sided groove 47.intermediate itsiendsin which the flattened head 48 of the screw 43 works. Each screw is-adjustably mounted in a split sleeve nut 50 having a threaded bore 50 and a wrench-engaging 44 carried in lugs 45 the cylinder head 46 53 of a split lug portion 54 of the shoe and a clamping bolt 55 extends lug andengages in the groove 52 with the result that said bolt prevents longitudinal displacement of said nut at all times and Iupon being tightened( up clamps said nut in adjusted position. Thus the loosening of the bolt 55 permits the vsleeve-nut to be turned so that the jack-screw 43 may be moved relative to the shoe so as to determine the release position of the free end of the shoe, and each shoe is connected by a spring 56 with a fixed part of the brake mechanism, as the head 46, so as shoe to a release position upon the release of Huid-pressure from the brake cylinder. Due to the slots and flattened portions of the piston-rod, levers and screws, the brake shoes are revented from moving laterally relative to t e drum and are held in proper alined position' relative thereto.

he particular. association and arrangement of the lever with the brakemember as however, forms the subject matter of my prior United States application Ser. o. 703,952, filed April 3, 1924.

With this construction the introduction of fluld-pressure between the pistons `35 causes lthem to move outwardly and thus swing the ends of the sh f application in the manner levers 42 outwardly and hence move the free oes outwardly causing a brake previously described and as the vfree ends of the shoes are through the split portions'of saidv and extending to move the end of said at less distance from the fulcrum of the lever than the point of fluid-pressure application an increased braking force results.`

I desire it to be understood that 'this invention is not to be limited to any specific form or arrangement of parts except in so far as such limitations are specified in the claims.

W'hat I claim as my invention is:

1. In brake mechanism of the class described, the combination with a rotatable brake drum, of a brake support, a pin on said support, anchor pin links pivotally mounted on said pin, a pair of brake shoes engageable with the drum, each shoe being connected near one end to one of said links, adjustable means associated with the link-sup ported end of each shoe to limit its swinging movement to release position, means acting on the free vends of said shoes to simultaneously move them into braking engagement with said drum, and means tol release said shoes from said drum.

2. In brake mechanism of the class describe the combination with a rotatable brake drum, of a brake support, an anchor pin link mounted on said support, a brake shoe engageable with said drum and connect-v ed adjacent one end to said link, means including an adjustable vstop-screw` on said link for limiting the swinging movement of said shoe to a release position, means acting on the free end of the shoe to move it into braking engagement with said drum, and means to release said shoe from said drum.

3. In brake mechanism of the class `de scribed, the combination with a rotatable brake drum, of 'a pair of brake shoes engageable with said drum, anchor pin links, each of said links being respectively pivotally connected to one shoe near one end thereof between the ends of said shoes, said support having a part between the link-supported ends of said shoes forming a pivotal'mounting for said links, means associated with the each shoe to limit its release position, and means for movin said shoes into engagement with said rum.

4. In brake mechanism of the class describe the combination with a rotatable brak'e drum, of a pair of brake shoes engageable with said drum, anchor pin links, each of said links being respectively ivotally connected to one shoe near one end) thereof and extending between the ends of said shoes, said support having a part between the link-supported ends of said shoes forming a pivotal mounting for said links, and means for moving said shoes into engagement with said drum.

In testimony whereof, I aiiix my signature.

NIELS A. CHRISTENSEN.

link-supported end ofV W 

